Unlocking the Capacity and Stability Limitations of Perovskite Electrodes and Achieving the Design of a Flame-Retardant Supercapacitor Through the “Tree Canopy” Structure

The present study depicts innovative electrode and electrolyte designs to achieve advanced supercapacitor performance and stability. The mechanism of how the electronic structure of substitution ions impacts the phase structure and properties of SrCoO3−δ was in-depth elucidated, overcoming the inherent trade-off between specific capacity and cycle stability in perovskite materials. The as-prepared SrCo0.925Sc0.075O3−δ electrode achieves a high capacity of 467.7 C g–1 (129.92 mAh g–1) at 1 A g–1, with retention of 97.4% of its initial capacity after 10,000 cycles. Inspired by canopy structures, a “branch”-like dual-network 3D gel system was created and in situ integrated with the electrode as the “trunk”. This unique structure offers robust mechanical strength and flame retardancy, establishing an efficient conductive network. Devices featuring this design show electrochemical stability and flexibility, ensuring safe operation at extreme temperatures while balancing the stability and energy density. This research opens avenues for high-performance supercapacitors and quasi-solid-state gel batteries tailored applications.